Aggressive behavior is typically adaptive for most species in the animal kingdom. Examples of this can be seen in maternal aggression to protect one’s young, and defense of a home territory; both of these contribute to the survival of an individual, and the species as a whole. But how is aggressive behavior mediated in the brain? Recent work indicates that the hippocampus in general, and the CA2 region in particular, is a crucial neural component in mediating social recognition and aggression. What CA2-specific mechanisms allow for such regulation?